Method for detecting body parameters

ABSTRACT

A method for detecting biometric parameters includes the steps of performing a bone graft procedure on a knee, providing a biometric sensor at the knee, and measuring a biometric parameter at the knee with the sensor. The sensor is capable of measuring parameters in an adjacent surrounding including pressure, tension, shear, relative position, and vascular flow. Data relating to the biometric parameter is transmitted to an external source and the data are analyzed to evaluate a biometric condition of the knee. A set of the sensors can be placed on the knee.

CROSS-REFERENCE TO RELATED APPLICATION

This application is a divisional of U.S. patent application Ser. No.11/391,988, filed on Mar. 29, 2006, now U.S. Pat. No. 7,918,887, whichclaims priority, under 35 U.S.C. §119, of U.S. Provisional ApplicationNo. 60/665,797, filed Mar. 29, 2005, and U.S. Provisional ApplicationNos. 60/763,761 and 60/763,869, both filed Feb. 1, 2006.

FIELD OF THE INVENTION

The present invention lies in the field of medical devices, inparticular, in the field of externally applied and embedded sensorsystems for detecting specific parameters of a physiological (e.g.,musculoskeletal) system and determining the exact anatomic site ofactivity, and methods for detecting parameters of anatomical sites.

BACKGROUND OF THE INVENTION

Sensor technology has been disclosed in U.S. Pat. Nos. 6,621,278,6,856,141, and 6,984,993 to Ariav and assigned to Nexense Ltd. (the“Nexense patents”).

It would be beneficial to apply existing sensor technology to biometricdata sensing applications so that health care personnel can determinecharacteristics of anatomic sites.

BRIEF SUMMARY OF THE INVENTION

It is accordingly an object of the present invention to provide a sensorsystem that can detect specific parameters (e.g., of a musculoskeletalsystem) and determine the exact anatomic site of activity and methodsfor detecting parameters of anatomical sites that overcome thehereinafore-mentioned disadvantages of the heretofore-known devices andmethods of this general type and that provides an externally appliedand/or embedded sensor to give healthcare providers real timeinformation regarding their patients. The information can includepathological processes as well as information regarding surgicalprocedures and implanted devices. The sensors can be activated byinternal or external mechanisms, and the information relayed throughwireless pathways. The sensor system will allow early intervention ormodification of an implant system and can use existing sensors. Forexample, the sensors disclosed in Nexense patents can be used.

With the foregoing and other objects in view, there is provided, inaccordance with the invention, a method for detecting biometricparameters including the steps of performing a surgical procedure on atleast one knee, implanting at least one biometric transceiver at the atleast one knee, transmitting a first energy wave from the transceiverinto a procedure area including at least one of the knee and an areaadjacent the knee, quantitatively assessing the behavior of the energywave with the transceiver, after transmitting the first energy wave:transmitting a second energy wave from the transceiver into theprocedure area; and quantitatively assessing the behavior of the secondenergy wave. At least one of the first and second energy waves arepulsed during transmission in a vibratory manner to stimulate theprocedure area in accordance with at least one detected parameter of theprocedure area. A current status is determined of the at least oneparameter of the procedure area selected from the group consisting ofpressure, tension, shear, relative position, bone density, fluidviscosity, temperature, strain, angular deformity, vibration, venousflow, lymphatic flow, load, torque, distance, tilt, shape, elasticity,motion, bearing wear, subsidence, bone integration, change in viscosity,particulate matter, kinematics, stability, and vascular flow with thetransceiver based upon a comparison between the assessed behavior of thefirst and second energy waves.

In accordance with another mode of the invention, there are provided thesteps of transmitting data relating to the at least one biometricparameter to an external source and analyzing the data to evaluate abiometric condition of the at least one knee.

In accordance with a further mode of the invention, a set of thetransceivers is provided on the at least one knee.

In accordance with an added mode of the invention, based upon theevaluation of the biometric condition of the at least one knee, acurrently ongoing interoperative procedure at the procedure area ischanged.

In accordance with an additional mode of the invention, based upon theevaluation of the biometric condition of the at least one knee, theanatomic condition relating to the procedure area is chronicallymonitored.

In accordance with yet another mode of the invention, energy is providedfrom outside the procedure area to the transceiver to power thetransceiver and, thereby, create the energy wave and quantitativelyassess the behavior of the energy wave.

In accordance with yet a further mode of the invention, the energy isprovided through at least one of an electromagnetic couple, a magneticcouple, a capacitive couple, an inductive couple, a sonic couple, anultrasonic couple, a fiber optic couple, an optical couple, and aninfrared couple.

In accordance with yet an added mode of the invention, a set of thebiometric transceivers is provided at the procedure area, an energy waveis transmitted from the transceivers into the procedure area, thebehavior of the energy wave is quantitatively assessed with at least oneof the transceivers, and, based upon the assessed behavior, a currentstatus of the at least one parameter is determined.

In accordance with yet an additional mode of the invention, a set of thebiometric transceivers is provided at the procedure area, energy wavesare transmitted from the transceivers into the procedure area, thebehaviors of the energy waves are quantitatively assessed with thetransceivers, and, based upon the assessed behaviors, a current statusof the at least one parameter is determined.

In accordance with again another mode of the invention, the areaadjacent the knee is a second bone different from the knee, and anenergy wave is transmitted from the transceiver, into the second bone,and back to the transceiver.

In accordance with again a further mode of the invention, the statusdetermining step is carried out by determining a current status of atleast two of the group of parameters with the transceiver.

In accordance with a concomitant mode of the invention, the at least onebiometric transceiver is embedded at the at least one knee.

Other features that are considered as characteristic for the inventionare set forth in the appended claims.

Although the invention is illustrated and described herein as embodiedin a sensor system that can detect specific body parameters anddetermine exact anatomic site of activity and methods for detection, itis, nevertheless, not intended to be limited to the details shownbecause various modifications and structural changes may be made thereinwithout departing from the spirit of the invention and within the scopeand range of equivalents of the claims.

The construction and method of operation of the invention, however,together with additional objects and advantages thereof, will be bestunderstood from the following description of specific embodiments whenread in connection with the accompanying drawings.

BRIEF DESCRIPTION OF THE DRAWINGS

Advantages of embodiments the present invention will be apparent fromthe following detailed description of the preferred embodiments thereof,which description should be considered in conjunction with theaccompanying drawings in which:

FIG. 1 is a diagrammatic, fragmentary, lateral view of a portion of aspine with a non-instrumented fusion of the spine and sensors accordingto the invention;

FIG. 2 is a diagrammatic, fragmentary, anterior-posterior view of thespine portion of FIG. 1;

FIG. 3 is a diagrammatic, fragmentary, lateral view of a portion of aspine with an intervertebral cage and sensors according to theinvention;

FIG. 4 is a diagrammatic, fragmentary, anterior-posterior view of thespine portion of FIG. 1 with sensors according to the invention inpedical screws

FIG. 5 is a diagrammatic, fragmentary, lateral view of a portion of aspine with an intervertebral disc implant and sensors according to theinvention;

FIG. 6 is a diagrammatic, fragmentary, enlarged cross-sectional view ofa sensor inserting instrument according to the invention;

FIG. 7 is a diagrammatic, fragmentary cross-sectional view of an upperfemur with sensors according to the invention implanted with theinstrument of FIG. 6;

FIG. 8 is a diagrammatic, fragmentary cross-sectional view of a vertebrawith sensors according to the invention implanted with the instrument ofFIG. 6;

FIG. 9 is a diagrammatic, fragmentary cross-sectional view of a femurwith sensors in a screw according to the invention;

FIG. 10 is a diagrammatic, fragmentary cross-sectional view of a femurwith implanted sensors according to the invention;

FIG. 11 is a diagrammatic, fragmentary cross-sectional view of avertebra with sensors according to the invention;

FIG. 12 is a diagrammatic, fragmentary, anterior-posterior,cross-sectional view of a knee joint with sensors according to theinvention;

FIG. 13 is a diagrammatic, fragmentary lateral, cross-sectional view ofa knee joint with sensors according to the invention;

FIG. 14 is a diagrammatic, fragmentary, cross-sectional view of a hipjoint with sensors according to the invention;

FIG. 15 is a diagrammatic, fragmentary, lateral cross-sectional view ofvertebrae with sensors according to the invention;

FIG. 16 is a diagrammatic, fragmentary, axial cross-sectional view of avertebra with sensors according to the invention;

FIG. 17 is a diagrammatic, fragmentary cross-sectional view of a kneejoint with ultrasound active sensors according to the invention;

FIG. 18 is a diagrammatic illustration of an ultrasound transmitter anda computer screen showing a knee joint with ultrasound active sensorsaccording to the invention being treated;

FIG. 19 is a diagrammatic, enlarged, cross-sectional view of a handleconnected to an implantable sensor body according to the invention;

FIG. 20 is a diagrammatic, enlarged, cross-sectional view of the handleof FIG. 19 disconnected from the sensor body;

FIG. 21 is a diagrammatic illustration of an infra-red visualizationsystem;

FIG. 22 is a diagrammatic illustration of an electromagneticvisualization system;

FIG. 23 is a fragmentary, partially hidden, anterior view of a kneejoint;

FIG. 24 is a fragmentary, partially hidden, lateral view of the kneejoint;

FIG. 25 is a fragmentary side elevational view of a ligament;

FIG. 26 is a fragmentary side elevational view of the ligament of FIG.25 with a ligament sensor clamp according to the invention;

FIG. 27 is a fragmentary side elevational view of the ligament andligament sensor clamp of FIG. 26;

FIG. 28 is a fragmentary side elevational view of the ligament of FIG.25 with sensors according to the invention attached thereto;

FIG. 29 is a fragmentary, cross-sectional view of a portion of anultrasonic cannula system according to the invention;

FIG. 30 is a fragmentary, cross-sectional view of a portion of a singlesensor cannula deployment device according to the invention;

FIG. 31 is a fragmentary, cross-sectional view of a portion of thecannula deployment device of FIG. 31 with multiple sensors;

FIG. 32 is a fragmentary, cross-sectional view of a portion of amulti-sensor cannula deployment device according to the invention;

FIG. 33 is a fragmentary side elevational view of an open knee surgerywith exclusion of soft tissue and cartilage and bone cuts with sensorsaccording to the invention deployed;

FIG. 34 is a fragmentary, cross-sectional view of a trocar tip accordingto the invention housing sensor elements;

FIG. 35 is fragmentary, cross-sectional view of an inserter for an arrayof sensors;

FIG. 36 is diagrammatic, side elevational view of a cutter housing anarray of sensors according to the invention;

FIG. 37 is a diagrammatic, side elevational view of a bone reamer;

FIG. 38 is a fragmentary, cross-sectional view of a sensor systemaccording to the invention implanted in a hip;

FIG. 39 is a fragmentary, cross-sectional view of a sensor systemaccording to the invention implanted in a femur;

FIG. 40 is a fragmentary, cross-sectional view of a cup sensor inserteraccording to the invention for deployment of multiple sensors;

FIG. 41 is a fragmentary, cross-sectional lateral view of two spinalsegments with a sensor implantion system according to the invention; and

FIG. 42 is a fragmentary, axially cross-sectional view a vertebral levelwith a sensor implanted through a pedicle.

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

Aspects of the invention are disclosed in the following description andrelated drawings directed to specific embodiments of the invention.Alternate embodiments may be devised without departing from the spiritor the scope of the invention. Additionally, well-known elements ofexemplary embodiments of the invention will not be described in detailor will be omitted so as not to obscure the relevant details of theinvention.

Before the present invention is disclosed and described, it is to beunderstood that the terminology used herein is for the purpose ofdescribing particular embodiments only and is not intended to belimiting. It must be noted that, as used in the specification and theappended claims, the singular forms “a,” “an,” and “the” include pluralreferences unless the context clearly dictates otherwise.

While the specification concludes with claims defining the features ofthe invention that are regarded as novel, it is believed that theinvention will be better understood from a consideration of thefollowing description in conjunction with the drawing figures, in whichlike reference numerals are carried forward. The figures of the drawingsare not drawn to scale.

An externally applied sensor system according to the present inventioncan be used to evaluate skin integrity and pathological pressure thatcan lead to skin ischemia and ultimately skin breakdown (Decubiti). Itis important to detect certain parameters that can lead to skinbreakdown. Elements such as pressure, time, shear, and vascular flow,for example, are important to detect. The specific anatomic location isneeded.

The sensor system of the present invention can be embedded in a thin,adhesive, conforming material that is applied to specific areas ofconcern. Exemplary areas include the heel, hips, sacrum, and other areasof risk. These sensors map out the anatomic area. If thresholdparameters are exceeded, the sensors inform a telemetric receiver that,in turn, activates an alarm to the nurse or other health careprofessional. In one specific application, the information is used tocontrol the bed that the patient is lying upon to relieve the area ofconcern. In particular, adjustment of aircells in the mattress can bemade to unload the affected area of concern.

The external sensor system can be configured in various ways. In anexemplary embodiment, a sensor is disposed within a thin, conformableadhesive that is applied directly to the patient's body and is poweredby a thin lithium battery. This sensor(s) documents specific parameterssuch as pressure, time, shear, and vascular flow. The sensortelemetrically informs a receiving unit and sets an alarm if certainpre-programmed parameters are exceeded. In one embodiment where a visualaid is provided (such as a computer screen displaying the patient's bodyoutline, the exact area of concern can be highlighted and, thereby,visualized by the health care professional.

Embedded sensors are needed to detect certain internal parameters thatare not directly visible to the human eye. These sensors will be used inspecific locations to detect specific parameters.

One way of embedding a sensor is through an open surgical procedure.During such a surgical procedure, the sensor is embedded by the surgeondirectly into bone or soft tissue or is attached directly to a securedimplant (e.g., a prosthesis (hip, knee)). The sensor system is usedduring the surgical procedure to inform the surgeon on the positionand/or function of the implant and of soft tissue balance and/oralignment. The sensor is directly embedded with a penetrating instrumentthat releases the sensor at a predetermined depth. The sensor isattached to the secured implant with a specific locking system oradhesive. The sensor is activated prior to closure for validating thesensor.

Another way of embedding a sensor is through a percutaneous procedure.The ability to implant sensors in specific locations is important toevaluate internal systems. Sensors of varying diameters can be implantedinto bone, soft tissue, and/or implants. The procedure is applied undervisualization supplied, for example, by fluoroscopy, ultrasound imaging,and CAT scanning. Such a procedure can be performed under local orregional anesthesia. The parameters evaluated are as set forth herein.The percutaneous system includes a thin instrument with a sharp trocarthat penetrates the necessary tissue plains and a deployment armreleases the sensor(s) at predetermined depth(s). The instrument couldalso house the necessary navigation system to determine the specificanatomic location required.

The parameters to be evaluated and time factors determine the energysource required for the embedded sensor. Short time frames (up to 5years) allow the use of a battery. Longer duration needs suggest use ofexternal activation or powering systems or the use of the patient'skinetic energy to supply energy to the sensor system. These activationsystems can be presently utilized. The sensors would also be activatedat predetermined times to monitor implant cycles, abnormal motion andimplant wear thresholds.

Information is received telemetrically. In one exemplary embodiment, thesensors are preprogrammed to “activate” and send required information ifa specific threshold is exceeded. The sensors could also be activatedand used to relay information to an external receiver. Furtherapplications allow readjustment of a “smart implant” to release specificmedications, biologics, or other substances, or to readjust alignment ormodularity of the implant.

The sensor system is initially activated and read in a doctor's officeand further activation can occur in the patient's house, with thepatient having ability to send the information through Internetapplications, for example, to the physician.

Software will be programmed to receive the information, process it, and,then, relay it to the healthcare provider.

The sensor system of the present invention has many differentapplications. For example, it can be used to treat osteoporosis.Osteoporosis is a pathological condition of bone that is characterizedby decreased bone mass and increased risk of fracture. It is wellaccepted that bone-mineral content and bone-mineral density areassociated with bone strength.

Bone density is an extremely important parameter of the musculoskeletalsystem to evaluate. Bone density measurements are used to quantify aperson's bone strength and ultimately predict the increased risksassociated with osteoporosis. Bone loss leads to fractures, spinalcompression, and implant loosening. Presently, physicians use externalmethods such as specialized X-rays.

The unit of measurement for bone densitometry is bone-mineral content,expressed in grams. Bone density changes are important in the evaluationof osteoporosis, bone healing, and implant loosening from stressshielding. Another important evaluation is in regard to osteolysis.Osteolysis can destroy bone in a silent manner. It is a pathologicalreaction of the host to bearing wear, such as polyethylene. Thepolyethylene particles activate an immune granulomatous response thatinitially affects the bone surrounding the implant. Bone density changeswill occur prior to cystic changes that lead to severe bone loss andimplant failure.

There are multiple external systems that can evaluate bone density. Theproblems with such systems encountered are related to the varioussystems themselves, but also to the socio-economic constraints ofgetting the patient into the office to evaluate a painless disease;coupled with the constricted payment allocations that cause longintervals between evaluations.

Sensors used according to the present invention allow evaluation ofchanges in bone density, enabling health care providers to know realtime internal data. Application of the sensors can assess osteoporosisand its progression and/or response to treatment. By evaluating changesin bone density, the sensors provide early information regardingfracture healing and early changes of osteolysis (bone changes relatingto polyethylene wear in implants).

Although the instrumentation various with different modalities, allrecord the attenuation of a beam of energy as it passes through bone andsoft tissue. Comparisons of results are necessarily limited to bones ofequal shape, which assumes a constant relationship between the thicknessof the bone and the area that is scanned. Moreover, the measurements arestrictly skeletal-site-specific; thus, individuals can be compared onlywhen identical locations in the skeleton are studied.

Dual-energy x-ray absorptiometry can be used to detect small changes inbone-mineral content at multiple anatomical sites. A major disadvantageof the technique is that it does not enable the examiner todifferentiate between cortical and trabecular bone. Quantitativeultrasound, in contrast to other bone-densitometry methods that measureonly bone-mineral content, can measure additional properties of bonesuch as mechanical integrity. Propagation of the ultrasound wave throughbone is affected by bone mass, bone architecture, and the directionalityof loading. Quantitative ultrasound measurements as measures forassessing the strength and stiffness of bone are based on the processingof the received ultrasound signals. The speed of sound and theultrasound wave propagates through the bone and the soft tissue.Prosthetic loosening or subsidence, and fracture of thefemur/tibia/acetabulum or the prosthesis, are associated with bone loss.Consequently, an accurate assessment of progressive quantifiable changesin periprosthetic bone-mineral content may help the treating surgeon todetermine when to intervene in order to preserve bone stock for revisionarthroplasty. This information helps in the development of implants forosteoporotic bone, and aids in the evaluation of medical treatment ofosteoporoses and the effects of different implant coatings.

The sensor system of the present invention can be used to evaluatefunction of internal implants. Present knowledge of actual implantfunction is poor. Physicians continue to use external methods, includingX-rays, bone scans, and patient evaluation. However, they are typicallyleft only with open surgical exploration for actual investigation offunction. Using sensors according to the present invention permitsdetection of an implant's early malfunction and impending catastrophicfailure. As such, early intervention is made possible. This, in turn,decreases a patient's morbidity, decreases future medical care cost, andincreases the patient's quality of life.

The sensors can be attached directly to implant surfaces(pre-operatively and/or intra-operatively) and/or directly to theimplant-bone interface. Sensors can be implanted into the bone and softtissue as well. In such an application, the physician could evaluateimportant parameters of the implant-host system. Exemplary parametersthat could be measured include: implant stability, implant motion,implant wear, implant cycle times, implant identification, implantpressure/load, implant integration, joint fluid analysis, articulatingsurfaces information, ligament function, and many more.

Application of sensors according to the invention allows one todetermine if the implant is unstable and/or if excessive motion orsubsidence occurs. In an exemplary application, the sensor can beconfigured to release an orthobiologic from an activated implantedmodule to increase integration. Alternatively and/or additionally, theimplant system with the sensors can be used to adjust theangle/offset/soft tissue tension to stabilize the implant if needed.

Sensors can be used to detect whether or not implant bearings arewearing out. Detectable bearing parameters include early wear, increasedfriction, etc. An early alarm warning from the sensor could enable earlybearing exchange prior to catastrophic failure.

A joint implant sensor can detect an increase in heat, acid, or otherphysical property. Such knowledge would provide the physician with anearly infection warning. In an exemplary infection treatmentapplication, the sensor can activate a embedded module that releases anantibiotic.

The sensors can be used to analyze knee surgeries. Such sensors can beplaced posteriorly in the knee to evaluate popliteal artery flow,pressure, and/or rhythm. A femoral implant sensor is placed anteriorlyto monitor femoral artery/venous flow, pressure, and/or rhythm. Aninternal vascular monitor can be part of the implant and include devicesto release antihypertensive or anti-arrthymic modules to modify vascularchanges when needed.

In one embodiment, the internal orthopedic implant is, itself, thesensor of the present invention. In a trauma situation, for example, thereduction screw can be both the implant and the sensor. Such a screw candetect abnormal motion at the fracture site and confirm increase indensity (i.e., healing). Such an application allows percutaneousimplantation of bone morphogenic protein (BMP) to aid in healing or apercutaneous adjustment of the hardware.

The sensor of the present invention can be used in spinal implants. Asensor placed in the spine/vertebrae can detect abnormal motion at afusion site. The sensor evaluates spinal implant integration at theadjacent vertebral segments and/or detects adjacent vertebral segmentinstability. Implanted sensors can activate a transitioning stabilizingsystem or implant and determine the areas of excessive motion to enablepercutaneous stability from hardware or an orthobiologic. Referring nowto the figures of the drawings in detail and first, particularly to FIG.1 thereof, there is shown a fragmentary lateral view of a fusion of aportion of the spine. An upper vertebra 10 is separated from a lowervertebra 20 by a disc 30. A bone graft 40 is covered first by aninferior facet 50 and second by a superior facet 60. FIG. 2 is ananterior-posterior view of the spine portion of FIG. 1 in which the bonegraft 40 is shown on either side of the disc 30 with opposing transverseprocesses 70. Sensors 1 according to the present invention can detectand transmit information regarding motion and loads of the vertebra 10,20 and are implanted in various spinal elements. The elements caninclude the spinal pedicles 80, transverse processes 70, facets, etc.

FIGS. 1 and 2 depict how sensors 1 of the present invention can be usedin non-instrumented fusions of the spine. The sensors 1 are activated atvariable times in the post-operative period. Abnormal or excessivemotion around the fusion “mass” helps detect a non-union, for example.

FIG. 3 depicts how sensors 1 of the present invention can be use ininstrumented spinal fusions. More particularly, the sensors 1 areincorporated into the “cage” instrumentation 130 in between an inferiorvertebral plate 110 and a superior vertebral plate 120. Such a sensor 1detects motion and load and is activated to transmit information in thepost-operative period to help determine if the fusion mass was solid.

FIG. 4 depicts how sensors 1 of the present invention can be use inpedicle screws 130. More particularly, sensors 1 are incorporated intothe pedicle screw 130 to help detect any abnormal motion betweenvertebrae in the fusion mass.

FIG. 5 depicts how sensors 1 of the present invention can be use ininvertebral disc implants (replacements). More particularly, anartificial disc replacement 140 has sensors 1 placed on the metal-boneinterface, for example. These sensors 1 detect loads as well as motionto help, intra-operatively, in the placement of the disc 140 and,post-operatively, determine stable integration of the disc-boneinterface. Internal sensors 2 detect “normal” motion between thearticulating disc internal interfaces to help confirm, post-operatively,that the disc replacement is functioning and optimize levels withvariable loads and spinal motion.

FIG. 6 depicts a sensor deploying instrument 150 is depicted as having ahandle 151 and a plunger 152. The handle 151 and plunger 152 allow theinsertion of the sensor 3 that is part of a trocar 153. The trocar 153can penetrate the cortex and the sensor 3 can be deployed. FIG. 7depicts the insertion of the sensor 3 in the femur and FIG. 8 depictsthe insertion of the sensor 3 in a vertebra. The sensor 3 can, then, bedecoupled with a coupling mechanism 154, for example, by an unscrewingor a derotating process. These body areas are used as examples becausethey are the most commonly affected area with regard to osteoporosis andtrauma relating to osteoporosis. The sensor 3 can vary in size fromseveral millimeters to over a centimeter. The sensor 3 can be implantedpercutaneously or in an open surgical manner.

The sensor 3 can be part of hardware used in the hip and/or the spine.The sensor 3 can be placed at various depths to allow evaluation of thecortex as well as the travecular bone. With two deployed sensors 3, thedistance between the sensors 3 can be determined at the area of concernand the power field that can be generated. The energy fields can bestandard energy sources such as ultrasound, radiofrequency, and/orelectromagnetic fields. The deflection of the energy wave over time, forexample, will allow the detection of changes in the desired parameterthat is being evaluated.

An exemplary external monitoring sensor system according to FIGS. 6 to 8enables on-contact nightly reads on bone mineral content and density.The sensor system can also enables a transfer of energy waves in avibratory pattern that can mimic load on the bone and lead to improvedbone mineral content and density. The sensors can also send energy wavesthrough or across an implant to, thus, aid in healing of a fracture.

Fracturing of a hip and a spinal vertebra is common with respect toosteoporosis and trauma. FIG. 9 depicts the use of a screw 4 as theinternal sensor. The fracture 160 is spanned by a compression screw 4and the sensors 4 are embedded in the screw 4. The sensors 4 in thescrew 4 can send energy across the fracture site to obtain a baselinedensity reading and monitor the change in density over time to confirmhealing. The sensors 4 can also be activated externally to send energywaves to the fracture itself to aid in healing. The sensors 4 can alsodetect the change in motion at the fracture site as well as the motionbetween the screw and bone. Such information aids in monitoring healingand gives the healthcare provider an ability to adjust weight bearing asindicated. Once the fracture is healed, the sensors 4 shown in FIGS. 10and 11 within the greater trochanter can now be activated to send energywaves to the other two sensors 4. This will enable continued evaluationof bone density. The sensors 4 can be activated with a sensor bed systemwhen the patient is asleep, for example. The energy source and receivercan be attached to the bed undersurface, for example. The receivedinformation can be evaluated every night if needed and sent by standardtelephonic measures to the doctor. The activation of the sensors atnight will enable specific interval readings during treatment ofosteoporosis by various medications.

External and internal energy waves sent with sensors according to theinvention can be used during the treatment of fractures and spinalfusions.

The use of ultrasound, pulsed electromagnetic fields, combined magneticfields, capacitive coupling, and direct electrical current have beenstudied in their effects on the up regulation of growth factors. PulsedUltrasound has shown to activate “integrins,” which are receptors oncell surfaces that, when activated, produce an intracellular cascade.Proteins involved in inflammation, angiogenesis, and bone healing areexpressed. These proteins include bone morphogenic protein (BMP)-7,alkaline phosphatase, vascular endothelial growth factor and insulingrowth factor (IGF)-1. The use of pulsed electromagnetic fields haveshown increased bone healing times in animals. Various waveforms affectthe bone in different ways.

A sensor system using quantitative ultrasound can be used to evaluatecalcaneal bone density externally. The system according to the inventionis attached to the patients' bed and, by using external ultrasound waveforms as shown in FIGS. 10 and 11, the bone density can be evaluated.The use of energy fields have been shown to stimulate the bone healingprocess. Stimulation can be effected with external measures, but use ofinternal sensor systems can change the waveforms and generate avibratory signal that can effectively “load” the bone. This affect isknown, by several orthopedic laws, to strengthen the bone cortex andeffectively be use in the treatment of fractures and osteoporoses and isdepicted in FIG. 10. The sensors in FIG. 10 are in the cortex or canal.The energy wave forms are sent to each other. They can be activated andreceived by an external system or be part of the sensor itself.Similarly, FIG. 11 depicts a vertebral segment in which sensors 4 sendenergy wave forms to each other and to an external receiver. Such asystem/treatment can be used to treat fractures and osteoporosis.

The sensor system according to the present invention depicts mainly thehip and spine, but can be applied to all skeletal segments of the body.FIGS. 12 to 18 depict various orientations of sensors according to theinvention for treating the knee, hip, and vertebrae.

FIGS. 19 and 20 depict one exemplary embodiment of a handle 170 that canbe releasably connected to an implantable sensor body 5. In thisembodiment, the handle has an exterior thread that screws into aninterior correspondingly threaded bore of the body 5.

Sensors according to the invention are used in multiple orthopedicapplications, including intra-operative joint implant alignment. Sensorsand monitoring devices/systems that can be used include any of thosewell known in the art, such as those described in the Nexense patents.Computer assisted surgery is also commonplace.

Presently, the use of pins in the femur and tibia, allow arrays to beattached to the bones. Such attachment helps in spatial orientation ofthe knee/hip joint during the operation. These arrays are recognized byinfrared optics or by electromagnetic devices (see FIGS. 21 and 22) toreplay the information into a recognized software system that allows thesurgeon to visualize the joint in a three-dimensional manner whileoverlaying the implant of choice on the bones. Problems encountered withthe application of such pins are many:

-   -   the need to penetrate bones outside the field of surgery;    -   post-op pain and drainage from the pin sites;    -   the possibility of pin loosening during the surgery as well as        blocking the arrays and infra-red light;    -   the pins require the surgeons to change the present positioning        during the procedure, which can be difficult; and    -   the electromagnetic field can be affected by various metals and        instruments that are used in the surgery.

The time associated with inserting the pins, locking the arrays,registering the joint topography contributes to a significantly longprocedure duration. There is still a need to individually touch multiplepoints on the femur and tibia to allow the computer to visualize thetopography of the knee. The time for transmission of information fromthe sensors to the receiver also causes a potential delay. Therefore, itwould be desireable to reduce or eliminate each of these problems.

Methods according to the invention include implanting the sensors in thefield of surgery, using the sensors during surgery, and using theimplanted sensors post-operatively to evaluate various desiredparameters.

FIG. 23 illustrates embedded sensors 6 in the femur and the tibia, andFIG. 24 illustrates sensors 6 in the patella. The ligaments showninclude the medial collateral ligament, the lateral collateral ligament,the anterior cruciate ligament, and the posterior cruciate ligament. Thesensors 6 are implanted prior to surgery in percutaneously and/orarthroscopically or intra-operatively through open surgery. FIG. 25depicts a ligament or tendon, FIG. 26 depicts a sensor clamp with acompressive and release handle, FIG. 27 depicts the deployment of thesensor and FIG. 28 reveals the deployed sensors in the ligament. Asshown in the steps depicted by FIGS. 25 to 28, the sensors can beembedded into the ligaments (FIG. 25 illustrates an exemplary ligament)by providing a sensor clamp (FIG. 26) that is placed around the ligament(FIG. 27) and secures the sensors thereto as shown in FIG. 28. They canalso be embedded into bone as shown later in FIG. 33. Standardradiograph techniques could be used to guide deployment angle and depth.

An ultrasonic cannula system 180 allows external non-radiatingvisualization of the sensor placement as shown in FIG. 29. The cannula181 houses the transmitter 182 and the receiver 183. The deploymentsensor 184 is, then, optimally positioned for insertion. The ultrasonicarm could, then, be used to obtain a rapid topography of the jointsurface and depth. The ultrasonic inserter sends energy waves to themultiple embedded sensors 7 that reflect to one another and back to theultrasonic transducer as shown in FIG. 17. FIG. 17 depicts theultrasonic sensors 7 using reflection techniques with the sound wave.The sound waves reflect off the end of the bone and the embedded sensor7 back to the receiver in the ultrasonic inserter. The receiver detectsthe reflected sound waves and activates the sensor output to a computerscreen for visualization as shown in FIG. 18.

The ultrasonic wave also exhibits a thru-beam to the tibia. Here, thetransmitter beams the ultrasonic wave to a separate receiver 190. Thefemur/tibia deflect the beam triggering the receiver output. The addedability of the embedded sensors 7 to continually reflect the ultrasonicbeam to the network of sensors 7 allows precise three-dimensionalinformation. The sensor 7 is programmed to compensate for irregularsurfaces and variable surface temperature. The measurement of bone isbased on the processing of the received ultrasound signals. Speed of thesound and the ultrasound velocity both provide measurements on the basisof how rapidly the ultrasound wave propagates through the bone and thesoft tissue. These measures characteristics permit creation of a rapidthree-dimensional geometry, which information can be externally sent tothe computer system that will allow integration of the prosthesis asshown in FIG. 18.

In order for the sensor system to obtain the needed informationregarding the spatial three dimensional topography of the joint, aminimum of three sensors are needed to be implanted into each bone thatis an integral part of the joint. The deployment of the sensor can be bya single cannula (FIG. 30) with one or several sensors (FIG. 31), or bya multiple sensor deployment cannula (FIG. 32). The sensor would have acalibrated trocar that would penetrate skin, muscle, ligament, tendon,cartilage and bone. FIG. 33 depicts the deployment of the sensors in anopen knee surgery where the soft tissue has been excluded and thecartilage and bone cuts have been made. A handle 190 houses a plunger191 that controls the depth of sensor deployment. See FIGS. 34 to 37.The minimal depth is determined by the amount of cartilage and bone tobe cut for the implantation of the prosthesis or implant. For example,in the femur and tibia, a minimum of 10 to 15 millimeters is cut. Thesensor is deployed deep with respect to that cut so as not to bedislodged during the procedure and to be able to be used in thepost-operative period. The trocar tip would house the elements of thesensor (FIG. 34) and, upon reaching the desired depth of deployment, thesensor 8 is inserted by a release of the locking mechanism (FIG. 19),which can be a screw, or a rotate-to-unlock joint, a break-away, or anyother decoupling mechanism.

Once the sensor system has been inserted, the external energy wave thatwill be used can be ultrasonic, or electromagnetic. The use of theoptical array method could, therefore, be avoided. The deflection of theenergy through the various mediums (cartilage and bone) and the timeelement of the energy wave is received by the sensors 8 and/or reflectedback to the external receiver. By having the various sensors 8, athree-dimensional model is depicted. This enables the surgeon to embedthe sensors (FIG. 33), use them during surgery (FIGS. 18 22) and, then,leave them implanted to be utilized after surgery (FIGS. 12 and 13).Accordingly, the speed of information transmission would be greatlyincreased and processed.

FIGS. 23 and 24 depict some elements of the knee joint soft tissue. TheACL, the PCL, the medial collateral ligament, and the lateral collateralligament are important for balancing of a knee joint during surgery. Thesensors are embedded into the ligament of a tendon by a clip mechanism(see FIGS. 25 to 28). The information is received and processed by asoftware system that is integrated into the computer-assisted jointsurgery device and presents a visual analogue of an intra-operativejoint (FIG. 22). Ligament tension, pressure, shear, etc. is evaluated. Asoft-tissue balancing grid aids in the surgeons approach regarding softtissue releases and component rotation.

FIG. 38 depicts a similar sensor system in the hip. The inserter issimilar to a single sensor inserter as shown in FIG. 38, or can bemodified as shown in FIG. 38. The inserter is configured to a cannulatedacetabular reamer that is used in standard hip surgery. The handle 200stabilizes the construct and the sensors 8 are deployed by depressing aplunger in the handle 200. FIG. 40 depicts a cup sensor inserter. Thecannulated holes allow deployment of the sensor 9. The construct can bemodified similar to FIG. 29 to include an ultrasonic component to helpvisualize the anatomy.

FIGS. 34 to 37 depict the development of “smart” inserters and “smart”instruments. The handle 210 of the inserter/instrument houses an arrayof sensors 8 to aid in the precise cutting of the bone (FIG. 36) as wellas the insertion of the prosthesis and sensors (FIGS. 35 and 37). Thesesensors 8 are spatially identified by the ultrasonic/electromagnetictransducer and receiver to allow confirmation that the implant/boneinterface was prepared appropriately, and that the implant was insertedto the appropriate depth and angle. The stability of a cemented or pressfit component could, then, be tested. Sensors implanted onto theprosthesis at the time of surgery or prior to surgery also allowprecision insertion and orientation of the prosthesis. Post-operativeimplant evaluation also is performed.

FIG. 39 depicts the insertion of the sensors 8 into the femur. Thesensor 8 can be deployed from the inside-out, from the outside-in, orincorporated into the distal centralizer of the prosthesis and or thecanal restrictor.

FIG. 41 depicts the lateral view of two spinal segments. The sensorinserter is shown in a percutaneous manner deploying the sensor into thevertebral body. FIG. 42 depicts an axial view of one vertebral level.The sensor 9 is implanted through the pedicle that has been prepared forinstrumentation.

The implanted sensor system following prosthesis insertion is depictedin FIG. 12, an anterior view of the prosthesis, and shows the kneejoint, femoral and tibial prostheses, the polyethylene implant, and theembedded sensors. FIG. 13 depicts a lateral view of a knee joint withthe prosthesis implanted with sensor system. FIG. 14 depicts a total hipprosthesis with the embedded sensor system. FIG. 15 depicts a lateralview of the embedded sensors within two segments of the vertebrae and animplant. FIG. 16 depicts a sensor system within a vertebral body with asuperior (axial) view of a prosthesis/implant.

The sensor system of the present invention can be used pre-operativelyto follow the progression of joint pathology and the different treatmentinterventions. The system can be used intra-operatively to aid in theimplantation of the prosthesis/instrumentation/hardware. In the spine,the affects on the neural elements can be evaluated, as well as thevascular changes during surgery, especially corrective surgery. Thesensors can, then, be used post-operatively to evaluate changes overtime and dynamic changes. The sensor are activated intra-operatively andparameter readings are stored. Immediately post-operatively, the sensoris activated and a baseline is known.

The sensor system allows evaluation of the host bone and tissueregarding, but not limited to bone density, fluid viscosity,temperature, strain, pressure, angular deformity, vibration,vascular/venous/lymphatic flow, load, torque, distance, tilt, shape,elasticity, motion, and others. Because the sensors span a joint space,they can detect changes in the implant function. Examples of implantfunctions include bearing wear, subsidence, bone integration, normal andabnormal motion, heat, change in viscosity, particulate matter,kinematics, to name a few.

The sensors can be powered by internal batteries or by externalmeasures. A patient could be evaluated in bed at night by a non-contactactivation system that can use radio frequency orelectromagnetic/ultrasonic energy. The sensor systems' energy signal canpenetrate the bed, activate the sensors, and transmit to a receiver thatalso can be attached to the bed. The sensors can be “upgraded” over time(e.g., with appropriate software enhancements) to evaluate variousparameters. The sensors can be modified by an external device, such as aflash drive. For example, a set of embedded sensors can monitor theprogression of a spinal fusion that is instrumented. Once a givenparameter is confirmed, the same sensors can be re-programmed to monitorthe adjacent spinal segments to predict increased stress and,ultimately, subluxation of an adjacent level.

Another feature of the sensor system is that it can rotate through aseries of sensor parameters during an evaluation period. An example ofsuch rotation can be evaluation of the bone density as the patientsleeps, and, following this, an evaluation of vascular joint fluidviscosity, and bearing surfaces. Such evaluation can occur on a fixedtime sequence on specific intervals or randomly as desired. Theinformation can telemetrically sent to the health care provider bycurrent telephonic devices. Likewise, the patient can be evaluated inthe doctor's office with an external sensor activator. The patientcould, then, go through a series of motions that allow the physician toevaluate implant function, including such parameters as load, torque,motion, stability, etc.

The software system houses the sensor information in a grid that allowsinterval comparisons. The physician, then, evaluates the data andfunctions that fall outside the standard deviations are highlighted,with these parameters being further evaluated.

Even though these sensor systems are discussed herein mainly withrespect to the knee, hip, and spine, these systems can be applied to anyof the skeletal systems in the body.

Use of the system has been explained in the description of the presentinvention for a musculoskeletal sensor system. It is to be noted,however, that the present invention is not so limited. The device andmethod according to the invention can be used with any need.

The foregoing description and accompanying drawings illustrate theprinciples, preferred embodiments and modes of operation of theinvention. However, the invention should not be construed as beinglimited to the particular embodiments discussed above. Additionalvariations of the embodiments discussed above will be appreciated bythose skilled in the art.

Therefore, the above-described embodiments should be regarded asillustrative rather than restrictive. Accordingly, it should beappreciated that variations to those embodiments can be made by thoseskilled in the art without departing from the scope of the invention asdefined by the following claims.

1. A method for detecting biometric parameters, which comprises:performing a surgical procedure on at least one knee; implanting atleast one biometric transceiver at the at least one knee; transmitting afirst energy wave from the transceiver into a procedure area includingat least one of the knee and an area adjacent the knee; quantitativelyassessing the behavior of the energy wave with the transceiver; aftertransmitting the first energy wave: transmitting a second energy wavefrom the transceiver into the procedure area; and quantitativelyassessing the behavior of the second energy wave; wherein at least oneof the first and second energy waves are pulsed during transmission in avibratory manner to stimulate the procedure area in accordance with atleast one detected parameter of the procedure area; and determining acurrent status of the at least one parameter of the procedure areaselected from the group consisting of pressure, tension, shear, relativeposition, bone density, fluid viscosity, temperature, strain, angulardeformity, vibration, venous flow, lymphatic flow, load, torque,distance, tilt, shape, elasticity, motion, bearing wear, subsidence,bone integration, change in viscosity, particulate matter, kinematics,stability, and vascular flow with the transceiver based upon acomparison between the assessed behavior of the first and second energywaves.
 2. The method according to claim 1, which further comprises:transmitting data relating to the at least one biometric parameter to anexternal source; and analyzing the data to evaluate a biometriccondition of the at least one knee.
 3. The method according to claim 2,which further comprises, based upon the evaluation of the biometriccondition of the at least one knee, changing a currently ongoinginteroperative procedure at the procedure area.
 4. The method accordingto claim 2, which further comprises, based upon the evaluation of thebiometric condition of the at least one knee, chronically monitoring theanatomic condition relating to the procedure area.
 5. The methodaccording to claim 1, which further comprises providing a set of thetransceivers on the at least one knee.
 6. The method according to claim1, which further comprises providing energy from outside the procedurearea to the transceiver to power the transceiver and, thereby, createthe energy wave and quantitatively assess the behavior of the energywave.
 7. The method according to claim 6, which further comprisesproviding the energy through at least one of an electromagnetic couple,a magnetic couple, a capacitive couple, an inductive couple, a soniccouple, an ultrasonic couple, a fiber optic couple, an optical couple,and an infrared couple.
 8. The method according to claim 1, whichfurther comprises: providing a set of the biometric transceivers at theprocedure area; transmitting an energy wave from the transceivers intothe procedure area; quantitatively assessing the behavior of the energywave with at least one of the transceivers; and based upon the assessedbehavior, determining a current status of the at least one parameter. 9.The method according to claim 1, which further comprises: providing aset of the biometric transceivers at the procedure area; transmittingenergy waves from the transceivers into the procedure area;quantitatively assessing the behaviors of the energy waves with thetransceivers; and based upon the assessed behaviors, determining acurrent status of the at least one parameter.
 10. The method accordingto claim 1, wherein the area adjacent the knee is a second bonedifferent from the knee, and which further comprises transmitting anenergy wave from the transceiver, into the second bone, and back to thetransceiver.
 11. The method according to claim 1, which furthercomprises carrying out the status determining step by determining acurrent status of at least two of the group of parameters with thetransceiver.
 12. The method according to claim 1, which furthercomprises embedding the at least one biometric transceiver at the atleast one knee.